Vania



E. R. COE AND R. M. GILSON.

RAILWAY SIGNALING.

APPLICATION FILED AUGJ, 1916.

1 ,3 1 0,608. Patented July 22, 1919.

2 SHEETS-SHEET l. FIG-.1 L

FIG.3

WITNESSES E. R. 00E AND R. M. GILSON.

RAILWAY SIGNALING.

APPLICATION FILED AUG.7. I916.

1,319,608, I Patented July 22, i919.

2 SHEETSSHEET 2- M E, Clo lj ns m A/ fla /V,

WITNESSES i To all whom it may concern.

vented certain new RAILWAY SIGNALING.

Be it known that we, ELMER R. C011 and ROBERT M. G LsoN, citizens of the United State s,,residing at Wilkinsburg and P1tts.'

burgh, respectively, in the county ofiAlleghenyand State of and useful Improvements in Railway Signalin following is a specification.

ur invention relates to signaling forelectrlc propulsion current as well as slgnallng current.

. One ob ect of-our 1nvent1on 1s to provide means for preventing a large part of the propulsion current from entering the windings of the,relays. This and other objects of our invention will appear in the following description.

.We shall describe one. form of apparatus embodying our invention and then point out Winding W the novel features thereof in claims.

In the accompanyingdrawings, Flgure 1 is a diagrammatic view showing one form and-arrangement of apparatus and circuits embodying ourinvention. Fig. 2 is a diagrammatic View showing, the electrical equivalent circuit through which winding W of relay R in Fig. l is connected to the track rails Fig. 3' is a view showing a vector diagram for the signaling current in the track connections of winding'W of relay R.

- similar parts in each of the several F ig.4 is a view showing. for the propulsion current a diagram similar to Fig. 3, Fig.

5 is a perspective view showing more in de- "tailthe relay R shown in Fig. 1.

Similar reference characters views. Referring first to Fig. 1, reference characters 4 and 5"designate the track rails of a railway, which rails are divided into sections by insulated the drawing only one section A-B, and the beginning and end respectively of the adjoining sections. For the control of traffic through section A-B we provide a signal S having a semaphore arm 20, which when in. the vertical position indicates proceed and when in the horizontal position indicates stop.. The positions of the signal semaphore are controlled by a local circuit, comprising a contact 0 and a source of current 22-, this control being such that the semaphore 20isin the vertical or the hori- Specificatio n of Letters Batent.

Pennsylvania, have inof which the roads in which the rails carry alternatof the vector diagrams.

, magnetizing refer to joints 2, there being shown in Patented July 22, 1919.

Application filed August 7, le s. Serial No. 113,433.

zontal position respectively according as contact 0 is closed or open. The contact 0 is operated (as we shall describe fully hereinafter). 'by a relay R comprising a rotor 23 responsive to currents in windings W and VV WindingW is constantly energlzed, being directly connected to a trans former P fed from a transmission line N, I

receiving alternating signaling current from generator H. inding W receives current from a track circuit which comprises the rails t and 5 of section -AB, a source of signaling current, here shown as a transformer M fed from transmission line N, connected to the rails adjacent one end of sec tion A B, and tus connected to the current responsive apparaother end of the section. the current responsive apparatus comprises an open core step-up transformer T, the secondary. of which is connected in series with a condenser C- and of such relative proportions that this secondary circuit is substantially As here shown,

resonant at the frequency of the signaling current, which for purposes of illustration we shall assume to 'be 60 cycles.

i Fig. 2 shows the electrical equivalent circuitfor this transformer and its secondary circuit when the ratio of transformation is 1 :1, as'we shall assume herein for simplicity cuit comprises an inductive impedance V in arallel withthe condenser C and winding V the impedance V being inserted in the diagrammatic circuit to account. for the current taken by the transformer, WlllCh current is rather large because of the open core.

Referring now to Fig. 3, vector OE rep resents the signaling current voltage on transformer T, and therefore also the volt-- age across condenser C and winding W in series. .The components of this voltage on.

the winding and the condenser are shown by vectors OL and LE respectively. Voltage OE causes a flow of current OD through impedance V, which current is equivalent to the magnetizing current of the'transformer. Condenser (land winding W being in resonance, take a current OK substantially in phase with voltage OE Vector Oh, the resultant of vectors OD and OK, shows the total current supplied to the transformer.

The current in winding W coacts with the This equivalent circurrent "in winding W to produce rotation,

of rotor 23 whereby the contact 0 of the relay is actuated to the closed position, as I shall now describe with'reference to Fig. 5. The; rotor 23 is mounted on a vertical shaft 26, which terminates at its upper end in arms i 27 Bell cranks 61 of a centrifugal governor G are pivotally. mounted in the slotted ends of arms 27 by means of pins 62, so thatthe bell cranks are free to swing in a vertical plane. A fly ball Gllis attached to one arm pin-connected to an arm 29 -riveted to a bracket 30 mounted on pivots 31. The contact a operated by the relay comprises a contact finger 21-fixed to" the bracket 30 by; I

' means of insulated studsi9, in such manner that the tip of the finger engages a stationary contact point 36. Contact 0 is normally held open by a weight W mounted on an arni &0, the extremity of which arm rests on a support 41 when the contact is open. Cur: rent in winding W causes. the rotor 23 to turn so that the balls of the governor fly apart. By means of the bell cranks 61, sleeve 6% is moved downwardly, so that it engages a collar 65 integral with'rod 28. The rotor is prevented by suitable means from moving vertically upward; consequently, rod 28 is pulled downward by means of governor G with a force depending-upon the speed of rotation of the rotor, which speeddepends upon the frequency of. the current. The weight W is soadjusted that its biasing force on bracket 30 is not overcome by the downward force on rod 28'until the rotor has accelerated to a speed corresponding to the frequency ofv the signaling current, namely,

.60. cycles. When, therefore; the signaling current energizes winding W the relay contact a closes thecircuit ofsignal S, which signal therefore gives'the proceed indication. Referring agaln to Fig. '1, when a vehicle V enters section AB, its wheels and axles form a path of low resistance from one track rail to" the other, so that nearly all of the signaling current is diverted from transformer T. The current in winding W is negligibly small and unable to continue to rotate rotor 23; The governorfly balls'are therefore unable to hold contact 0 closed against the action of weight W, so that the circuit for signal S is broken and the semaphore 20 drops to theistop position. Thus it appears that due to the flow of'signaling current in the track circuit, the relay R causes signal S vto indicate proceed or stop according totwhether or notthere is a train in section AB.

. Propulsion current forthe operation of: cars or trains along the railway is furnlshed" by an alternator G, one terminal. of which is connected to a trolley wire or third rail L,

and the other terminal of which is grounded to the track rails, The propulsion current'has-a lower frequency than the signal- .ing current, generally 25 cycles, which value we shall assume for present purposes; This propulsion current flows from one terminal of the generator through wire L, vehicle .V, track rails @and 5 in parallel. to the other terminal of the generator G. Impedance bonds I are provided for'passing the propulsion current around the insulated joints without interfering with' the flow of the signalingcurrent as well understood in the .art. In flowing through the vehicle the current drives the propulsion motors which we have not shown on the drawing.

For a variety of causes, to, mention only unequal bonding combined with unequal grounding of the track rails, it may happen that for the propulsion current the voltageof one track rail in section AB is. higher than the voltage of the other rail, so that a part of the propulsion current flows from one track rail to the formerT.

If the propulsion lcurrentin transformer T should enter winding W ofrelay R, in excessive amount, it would cause a saturation of the stator core and retard the speed of rotor 23 so that'contact '0 would open and signal S would indicate stop, even though there were no train in section A B. Byour invention the portion of the propulsion current that actually reaches Wllldfother through the transing W is reduced to a small fraction of the v current entering transformer T from 'the' track rails. This is shown by the vector diagram Fig. 4, wherein OK is a vector representing the propulsion current in winding W assumed for present purposes equal in amount to the signaling current in the relay. The voltage then on relay winding W,"

v is vector 'OL',smaller than the correspdnding vector OL in Fig. 3, because the inductan'ce of the winding decreases with the freguency ofthe current The voltage on conenser C is larger than before, as shown by vector LEC, because the reactance of a condenser varies inversely as the frequency. The voltage on the transformer, or the voltage on coil 'V in the electrical equivalent diagram Fig; 2, .is thevector sum of the above two voltages, i. 6., vector' O E. The magnetizing current of the transformer or the current through impedance Vof Fig. 2, is represented .by vector" OD, larger than the corresponding'vector OD of Fig. 3,.because. the voltage on the transformer is higher and because the magnetizing current of a transformer increases with decrease of frequency.

- The total propulsion current,then, supplied ing.

to the transformer is shown by vector O'F,

the sum of the magnetizing current OD" and the current OK" in the relay windthe correspondingvector.OFin Fig. 3,it is' apparent that for the same amount of current in winding -W afar greater propulsion current finust flow into the transwhen the relay is directly connected to the rails, as usualin present practice, Whereas atnthe same time the slgnaling current is practically unaifected in its operation of the relay. Thus" considerable propulsion cur- I 'rent'may' flow into transformer T before enough of thiscurrent enters the relay .to iopen contactc. .f

If it happens that propulsion current en'- l ters both windings W andW this current circuit for said transformer produces rotation of rotor 23 even when the signaling current'is not present in 'wind-,

mg W Due to the lower frequency, however, the speed of rotation is not as high as required for the operationof the relay contact c by the centrifugal governor, as well understood in the art, and thepropulsion current can therefore under no circumstances 0 and a falsecause a false closure'iofcontact proceed indication of signal S.

Although we have hereinshown and described only one form of apparatus embodying our invention, it is understood that various changes and modifications may be made, therein within the scope of "the appended claims,;without departing from the spirit and scope of our invention.

Havingthus described our invention, what we claim is:

'1. In combination, energizing winding, a transformer having an open magnetic circuit, and a secondary L including said relay winding, wherebywhe n the primary of said transformer is supplied with equal said relay winding receives considerably more current of the higher frequency than of the lower frequency.

2. In combinat on, induction motori having twowindings, a contact, speed responsive means for governing said contact by said motor, means for -b supplying current to one winding, means for supplyingcurrentto the other winding,

. said latter means comprising an open core transformer, having a magnetizing current increasing w th decrease of frequency, a

1 condenser and said last-mentioned relay By comparing the vector OI with winding is of the propulsion current on the relay is considerably winding connected in the ing said contact by said motor,.mea'ns for a relay comprising an.

a relay comprising an of said transformer, saidcircuit being resonant .at a predetermined frequency, so that when saidtransformer is supplied with cur rent of said predetermined frequency and also with current of a lower frequency, said energized by a proportionately greater amount of the former current than of the latter current.

3. In combination, a relay comprising an induction motor having two w ndings, a contact, speed-responsive means for governmg said .contact by said motor, means for supplying current to one winding, means for supplying current to the other winding,

i said latter means comprising a transformer,

a condenser and said last-mentioned relay secondary circult of said transformer, 'sa1dc1rcu1t being resonant ,at a predetermined frequency-and said .transformerfhaving an open core so that it has a high magnetizing current at a lower frequency than .said predetermined 'fre-' quenoy, so that when said transformer is en; ergized by currents of said frequencies, said winding is energized proportionately more by one current than by the other. J

4a,- In combination, a relay comprising an" induction motor having two windings, a contact, speed responsive means for govern supplying current to one winding, means for supplying'current to the other winding, said latter means comprising anopen core transformer,'and a secondary circuit therefor comprising a condenser and said lastmentioned relay winding, said circuit being resonant at a predetermined frequency. 5.- In combination, a relay comprising an. energizing winding, a transformer having an open magnetic circuit 5 a circuit including in series the secondary winding of said-trans- I former, the said relay winding and a condenser; said circuitbeing resonant at a predetermined-frequency, whereby when the primary of said transformer is suppliedwith current at said predetermined frequency and also with an equal current at a lower frequency, said relay winding-receives'considerably more current at the predetermined 115 frequency than at the lowerfrequency,

erated by said motor for actuating said con tact when current of a predetermined 'frequency is supplied .to both of said motor windings, a transformer having an open magnetic circuit, and a secondary circuit for said transformer including one of said; re-

lay windings, whereby when the primary of plied by the secondary of the transforiner receives considerabiy more current of the predetermined frequency than of the lower frequency. v In testimony whereof we affix our signatures in presence of two witnesses.

ELMER R. COE. p ROBERT M. GILSONI Witnesses: r

A. HERMANVVEGNER,

IETHEL- C. DURHAM. 

